Jacob keller



' (No Model.)

J. KELLER. HYDRAULIG BRAKE MECHANISM.

Paftented May 15,1894.

UNITED. STATES PATENT OFFICE.

JACOB KELLER, OF BASLE, SWITZERLAND.

HYDRAULIC BRAKE MECHANISM.

" SPECIFICATION forming part of Letters Patent No. 520,001, dated May15, 1894.

Application filed August 22, 1893. $arial No. 483,773- (No model.)

T0 at whom it may concern:

Be it known that I, J ACOB KELLER, a citizen of the Republic ofSwitzerland, residing at Basle, canton of Basle Town, Switzerland,haveinvented certain new and useful Improvements in Hydraulic BrakeMechanism;

and I do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

This invention for improvements in hydraulic brake mechanism has for itsobject to providea mechanism adapted to regulate the speed of a shaft orpulley or to stop its motion by opposing a hydraulic resistance to itsmotion; and consists essentially of a small rotary pump arranged in andforming part of the object to be braked and whose suction and deliveryports are connected by a passage whose area is adjustable. The pump andpassages are filled with aliquid such as glycerine. It will readily beseen that as the pump rotates with the object to be braked it will causea flow of liquid through the adjustable passages first in one directionand then in the opposite and that the resistance to motion will varywith the area of the passage.

In the accompanying sheet of illustrative drawings which shows the brakemechanism applied to a chain hoisting pulley, Figure 1 is I is alongitudinal section of the brake mechanismconstructed according to thisinvention,

and Fig. 2 is a left side elevation and Fig. 3

a right side elevation partly in section, the covers being removed, ofthe same and Fig. 4 is a longitudinal section on the line a:-x, Fig. 2,of the chain pulley and covers.

The hollow chain pulley b, provided with end covers 12 19 is mountedloosely and axially on the shaft a. An eccentric c fixed on the shaft orand provided with a strap f and rod 9 is arranged in a cylinder I formedaxially Within the pulley Z) in such manner that as the pulley b rotateson the shaft a the point of contact of the eccentric strap f and innersurface of the cylinder I gradually passes round the inner circumferenceof the rod 9 is guided ina slot in atrunnion hworking in bearingsparallel to the shaft a. On the rotation of the pulley b, the eccentricand strap form a kind of rotary piston for the cylinder I and the rodforms an abutment dividing the suction from the delivery, the wholeforming a rotary pump, there is a suction to the rear of the point ofcontact of the strap and inner wall of the cylinder and a pressure tothe fore. The suction and pressure spaces are always in communicationwith one another by the passages (1%, (i in which are the pointed screwss s, for adjusting the area of the passages at these points. The chamberand passages are filled with a liquid such as glycerine.

It will be seen that on rotating the pulley there will be a fiow ofliquid through the passages 61, (Z first in one direction and then inthe reverse and that the resistance to this flow and consequently to themotion of the pulley is graduated by means of the screws .9 s.

In order to avoid dead points and to render the working of the mechanismmore smooth the pulley is divided into two cylinders I II by a centralcross partition 0 the eccentric e with its strap f and rod g working inone cylinder and a corresponding eccentric 6 with its strap f and rod gWorking in the chamber II and being fixed to the shaft or opposite, thatis at one hundred and eighty degrees to the eccentric e. The cylinder eis provided with passages d d and with pointed screws s .9 correspondingto the passages d d and pointed screws 5 respectively.

The eccentrics straps and rods extending the full width of the cylindersI or II and the rods gg are guided in slots in the trunnions a h workingin recesses in the covers b b and partition 0. The diameter of thecylinders I and II as will be seen from the above description is equalto the diameter of an eccentric strap together with double theeccentricity of the eccentric.

In order to prevent the escape of liquid the covers b b are fitted withstufling boxes as clearly shown.

The whole apparatus occupies a very small space and can replace theusual nave of a pulley or drum.

Instead of fixing the shaft a the pulley b may be fixed in which casethe apparatus will serve as brake for the shaft a or will regulate thespeed of a wheel fixed on the shaft a.

What I claim, and desire to secure by Letters Patent, is

1. Abrake mechanism consisting of a shaft, of a cylinder mounted looselyand axially on the shaft, of an eccentric fixed on the shaft within thecylinder and extending the full length of the cylinder, of an eccentricstrap working on the eccentric and also extending the length of thecylinder and adapted to make contact with the inner wall of thecylinder, of an eccentric rod secured to the strap and Working in arecess in the cylinder walls and also extending the full length of thecylinder of a trunnion mounted in the recess and in which the eccentricrod slides, and of a means for adjusting the area of a passageconnecting the cylinder immediately on either side of the said recess,the whole substantially as set forth.

2. Abrake mechanism consisting of a shaft,

of two cylinders mounted loosely and axially on the shaft, of twoeccentrics fixed on the shaft within the cylinder opposite to oneanother and extending the full length of the cylinders, of eccentricstraps working on the eccentrics and also extending the lengths of thecylinders and adapted to make contact with the inner walls of thecylinders, of eccentric rods secured to the straps and working inrecesses in the cylinder walls and also extending the full lengths ofthe cylinders of trunnions mounted in recesses in which the eccentricrods slide, and of means for ad- 3' usting the areas of passagesconnecting each cylinder immediately on either side of the saidrecesses, the whole substantially as set forth.

In testimony whereof I affix my signature in presence of two Witnesses.

JACOB KELLER. Witnesses:

GEORGE GIFFORD, O. BURCKHARD.

